ABSTRACT
The island of Murano (Venice, Italy) is famous worldwide for its artistic glass production. Diarsenic trioxide was a main ingredient of the raw glass mixture until 2015, when the authorisation process of European REACH Regulation (Registration Evaluation Authorisation of Chemicals) entered into force, effectively forbidding the use of arsenic. A total of 3077 PM10 samples were collected across the Venice area in 2013-2017. This period included the REACH Sunset Date (May 2015). High arsenic concentrations were recorded in Murano before the Sunset Date (average 383 ng/m3), representing a serious concern for public health. Other sites in Venice complied with the EU target value. In 2013, concentrations were 36-folds higher than model estimation computed over the maximum-allowed emission scenario. Polar plot analysis indicated Murano as the major source of arsenic contamination. The concentration significantly dropped after the REACH implementation, thus meeting the European target values. However, high peaks of arsenic were still detected; inspections on raw and finished glass materials confirmed that some factories were still using arsenic. Results reported serious airborne arsenic pollution in Murano before the REACH implementation. This work represents an interesting case study on the effectiveness of the European REACH process.
ABSTRACT
Venice Marco Polo Airport (VCE) is one of the most important airport of Italy, but is also placed in a delicate context; due to the proximity of the airport to the Venice historical city and the fragile ecosystem of the Lagoon that surround the city. For all these reasons the priority was to assess the possible impact of Marco Polo Airport in Venice area. For this reason a collaboration between Save Spa, the company that manage Marco Polo airport, and the Department of Environmental Sciences, Informatics and Statistics, of Ca' Foscari University was stated in order to: (I) understand the impact on air quality of an airport structure in a vulnerable context (II)analyze the airport emission trend (III) analyze how the number of flights and aircraft type can influence emission. During this collaboration two methodologies for emission estimation (EMEP-CORINAIR and Emissions and Dispersion Modeling System, EDMS) were tested in order to understand what was the best tool to estimate aircraft exhausts emissions. Results, reported in this paper show a deep difference between the two methods, with a general decrease in emission estimation using EDMS model, except in a NOxand HC cases. Subsequently the difference in emission in two typical operating days of 2009 was investigated. Results show that schedule and number of flights affect deeply emission estimation.
ABSTRACT
The integration of chemical and biological data in aerosol studies represents a new challenge in atmospheric science. In this perspective it will be possible to gain a clearer and deeper comprehension of biogeochemical cycles in the atmosphere. In this view, this study aimed to investigate the relationships occurring between bacterial populations and PM chemical composition in one of the most polluted and urbanized areas in Europe: the Po Valley (Italy). Moreover, seasonality, long- and short-range transports were also evaluated to investigate the influence on airborne bacterial communities. PM samples were collected in two cities of the Po Valley (Milan and Venice) characterized by different meteorological conditions and atmospheric pollutant sources. Samples were analysed for water-soluble inorganic ions (WSIIs) and bacterial community structure. Chemical and biological data were jointly processed by using redundancy discriminate analysis (RDA), while the influence of atmospheric circulation was evaluated by using wind ground data and back-trajectories analysis. Results showed strong seasonal shifts of bacterial community structure in both cities, while a different behaviour was observed for air mass circulation at Milan ad Venice sites: long-range transport significantly affected bacterial populations in Milan whereas local ground wind had more influence in the Venice area. Moreover, difference in taxonomic composition can be mostly addressed to the characteristics of sampling sites. This evidence could suggest that, while PM composition is influenced by long-range transport, bacterial populations are affected, besides transport, by other factors (i.e., season and sampling site location). This perspective allow to better understand and explain airborne bacterial community behaviour.
Subject(s)
Air Microbiology , Air Pollutants/analysis , Environmental Monitoring , Particulate Matter/analysis , Seasons , Cities , Italy , Particle SizeABSTRACT
Despite airborne microorganisms representing a relevant fraction of atmospheric suspended particles, only a small amount of information is currently available on their abundance and diversity and very few studies have investigated the environmental factors influencing the structure of airborne bacterial communities. In this work, we used quantitative PCR and Illumina technology to provide a thorough description of airborne bacterial communities in the urban area of Milan (Italy). Forty samples were collected in 10-day sampling sessions, with one session per season. The mean bacterial abundance was about 104 ribosomal operons per m³ of air and was lower in winter than in the other seasons. Communities were dominated by Actinobacteridae, Clostridiales, Sphingobacteriales and few proteobacterial orders (Burkholderiales, Rhizobiales, Sphingomonadales and Pseudomonadales). Chloroplasts were abundant in all samples. A higher abundance of Actinobacteridae, which are typical soil-inhabiting bacteria, and a lower abundance of chloroplasts in samples collected on cold days were observed. The variation in community composition observed within seasons was comparable to that observed between seasons, thus suggesting that airborne bacterial communities show large temporal variability, even between consecutive days. The structure of airborne bacterial communities therefore suggests that soil and plants are the sources which contribute most to the airborne communities of Milan atmosphere, but the structure of the bacterial community seems to depend mainly on the source of bacteria that predominates in a given period of time.
